1. Field of the Invention
The present invention relates to an electrical connector, and, more particularly, to an electrical connector for a motorcycle rectifier.
2. Description of the Related Art
In an electrical connector with two parts where one connector part has at least one male terminal and the other connector part has at least one female terminal, a common problem when electrically connecting the two parts is contact resistance between corresponding male and female terminals. If the connector is part of a relatively high current circuit, the effect of contact resistance between corresponding male and female terminals is amplified according to Ohm's Law, i.e., the voltage drop across the terminal pair is the current through the terminal pair multiplied by the contact resistance between the terminal pair, assuming the terminals' resistance are negligible. The higher current thereby produces a higher voltage drop across the terminal pair. Concurrently, high contact resistance can act as a current limiting device which limits current to the electrical load connected to the electrical connector. The effect of reduced voltage and/or current to the electrical load can limit the performance of the electrical load, shorten the useful life of the electrical load and/or render the electrical connector essentially non-functioning.
Additionally, the heat generated by the electrical connector according to the equation P=I2R (where P is the heat loss by the connector, I is the current through the connector and R is the contact resistance) can start a negative spiral which ultimately leads to a failure of the connector. For example, the heat generated by the current through the connector and the contact resistance can breakdown the insulation associated with the connector. The heat generated by the electrical connector can also degrade the contact between connector terminals by accelerating corrosion, oxidation, pitting, etc., of the terminals dependent on environmental factors, and connector design and composition.
The contact resistance between two terminals in a connector is proportional to the resistivity of the current carrying materials of the terminals and inversely proportional to the contact area between the terminals. From these relationships it is desirable therefore to have as large of an area of the terminals in mutual contact and also have the area of the terminals in mutual contact free from relatively high resistivity materials such as metal oxides.
A known connector terminal design includes a barrel shaped female terminal and a rod shaped male terminal, both with circular cross-sections. Ideally, the entire inside surface of the female barrel is in contact with the entire outside surface of the male rod; however, this ideal surface contact is never realistically achieved. According to known design principles and achievable, cost effective manufacturing tolerances, the male rod when inserted into the female barrel tends to arrive at a three point mutual contact which has a very small mutual contact area. Further, the three points in contact when the male terminal begins insertion into the female terminal are different than the three points in contact when the male terminal is fully inserted into the female terminal. Stated differently, the three point mutual contacts between the male and female terminals can wander around the circumferences of the corresponding terminals. The final surfaces in mutual contact after complete insertion of the male terminal therefore have been subjected to minimal, if any, frictional forces that would tend to scrape away higher resistivity material surface layers associated with the terminals, such as a metal oxide surface layer.
What is needed in the art is an electrical connector with male/female terminal pairs which provide consistently low contact resistance and which are reliable and cost effective to manufacture.